It will be interesting to see. We haven't seen Pettis fight often so I don't see why people are assuming he hasn't improved a ton.
The big question, imo, isn't Pettis takedown defense. I think he's good enough to stop some but not all of Bendo's takedowns. It's if he can out grapple Bendo again. Back in the WEC days Bendo was constantly caught in submission attempts when he was in top position.
The one thing in Pettis favor is Bendo hasn't fought many guys as well rounded as Pettis in the Ufc. LIke Gsp, Bendo is great at using his well rounded abilities to exploit his opponents weaknesses. Unlike Diaz(wrestling), Guida(striking), Jim Miller(athletic ability) Pettis is dangerous everywhere. The one guy Bendo did fight who was very well rounded is Edgar who probably should of got the nod in their 2nd fight and was very competitive with Bendo in their first fight.
Either way the lw title fights are going to be stellar this year. We could see Bendo vs Gil in April, Pettis vs Bendo/Gil in July/August and Bendo/Gil/Pettis vs Alvarez in the fall. Man I love the lw division.